Atherosclerosis, a form of arteriosclerosis, is characterized by internal thickening of the major blood vessels due to localized accumulation of lipids, of which cholesterol and triglycerides, comprise the major constituents. Furthermore, it has been found that those suffering from the disease exhibit abnormally high blood cholesterol levels. While the etiology of the disease is not fully understood, it is believed that cholesterol plays an important role. A high level of blood triglycerides is also a risk factor for atherosclerosis. (The Heritable Hypoliproteinemias and Atherosclerosis, C. J. Glueck and R. W. Fallat, Lipids, Lipoproteins and Drugs, pp. 169-183 and 305-316, Plenum Press, 1975.
In the advanced stages of the disease, plaques, comprising cholesterol and other .beta.-lipoproteins, accumulate in the aorta coronary, cerebral, and peripheral arteries of the lower extremities. As these plaques increase in size the danger of fibrin deposition, possibly resulting in thrombosis and occlusion, is enhanced.
While no sure method has been found for preventing the disease, it has been recommended that dietary habits be observed that will insure low .beta.-lipoprotein levels. Besides stringent dietary management, various therapeutic agents such as estrogens, thyroxine analogs and sitosterol preparations have been used to lower the cholesterol levels of those afflicted with the condition.
It has now been found that various thiophene derivatives are effective hypolipemic agents because of their ability to lower the blood lipid level of warm blooded animals. Consequently, these compounds can be expected to be useful in the treatment of atherosclerosis and related cardiovascular diseases which are associated with elevated blood lipid levels.
Obesity represents a state of increased body fat which may decrease longevity, aggravate the onset and progression of other diseases, (e.g., heart disease, diabetes, gallstones) and impact on one's social or economic status. (The Obese Patient, G. A. Bray, Vol. IX in the series "Major Problems in Internal Medicine", W. B. Saunders Co., 1976.)
It has also been found that the thiophene compounds of the invention selectively reduce body fat by suppressing its biosynthesis and thus are useful in the treatment of obesity.